This invention relates to sprag clutches, and particularly to energizers as used in sprag clutches for urging the sprags into mechanical engagement with the inner and outer races thereof.
Sprag clutches are utilized principally in indexing operations, such as impact hammer drills for boring. Under high rates of impact, for example those at or exceeding 3,000 impacts per minute, the energizers of such clutch applications have relatively short useful lives, and must consequently be replaced frequently. Conventional energizers are coiled garter springs made of steel, which in addition to chattering against and wearing the energizing surfaces of the sprags, suffer loss of spring tension during useful life, resulting in a continuing increase in response time.